1. Field of the Invention
The present invention relates to a module type mini BNC connector, and particularly to a mini sized and easily fabricated module type BNC connector.
2. Description of Related Art
In order to enhance signal transmission quality of the BNC connector with metal outer casing, the applicant has filed an invention in Taiwan with Application No. 91206496 and in U.S. with application Ser. No. 10/173,462, entitled BNC CONNECTOR WITH ALL METAL OUTER CASING. The prior art basically has a metal cover is joined to an outer casing at the lower end thereof to constitute a space for receiving the BNC connector and the lead wires extending from the rear side of the BNC connector. Hence, the power loss rate of the BNC connector during the signal being transmitted can be reduced and the electromagnetic wave interference generated by the foreign electronic parts can be resisted so as to enhance the quality of the transmitted signal.
However, the preceding BNC connectors are large sized but it is a trend that smaller sized BNC connectors are needed. In order to comply with the trend, the present inventor further has filed a Taiwanese application, which was assigned Application No. 91217859, and a U.S. patent application entitled “MINI BNC CONNECTOR”. The mini BNC connector is provided with double casings so that it is capable of providing better signal transmission quality and being fabricated more conveniently.
Currently used various module type mini BNC connectors as shown in FIGS. 1A, 1B, 1C, 1D and 1E provide casings thereof are composed of front casings 30, 32, 34, 36, 38 and rear casings 31, 33, 35, 37, 39. The front casings 30, 32 at the external parts thereof have an arched shape and the front casings 34, 36, 38 at the external parts thereof have a square shape respectively. The rear casings 31, 33, 35, 37 at external parts thereof have screw threads 311, 331, 351, 371 respectively and the real casings 31, 35 at the external parts thereof have ring plates 312, 352 respectively behind the screw threads 311, 351.
As the foregoing, the conventional module type mini BNC connector adopts a two piece combined outer casing and although it is easy for the terminals and the insulators to mount in the outer casing, the two piece parts of the outer casing have to be fabricated independently before being joined to each other and more material cost and longer working time are needed. Further, the front and the rear casings have a very tiny size respectively and it is hard to be assembled so that it is easy to result in a change of electrical performance of the respective terminal and become defective product in case of occurring a slight deviation of position. Accordingly, it is time consuming and requires more labor with more serious defect rate so that higher production cost has to be spent.